Quinuclidine compounds having quaternary ammonium group, its preparation method and use as blocking agents of acetylcholine

ABSTRACT

The invention relates to the quinuclidine compounds of formula I having quaternary ammonium group, its preparation, and the pharmaceutical composition comprising an effective amount of the compound of formula I. The compound and the composition are used to prevent and treat the diseases by blocking acetylcholine receptor. 
                         
Wherein: R 1  is selected from C 1-12  saturated straight-chain alkyl and cycloalkyl; R 2  is selected from C 1-12  saturated straight-chain alkyl or straight-chain alkyl; and X is selected from halogen ion, organic and inorganic acid radical.

CROSS REFERENCE TO RELATED APPLICATION

This application is a Divisional application of U.S. application Ser.No. 11/033,653, entitled USE OF TA-CAPPED METAL LINE TO IMPROVEFORMATION OF MEMORY ELEMENT FILMS and filed on Jan. 12, 2005, theentirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to an anticholinergic agent, especially toquinuclidine compounds having a quaternary ammonium group andpreparation methods of the same, compositions comprising one or moresuch compound(s), and the use of the above compounds in preparation ofanticholinergic agents.

BACKGROUND OF THE INVENTION

Acetylcholine (ACh) is a kind of neurotransmitter released from thecholinergic nerve ending including motor nerve fiber, vegetative nervepreganglionic fiber, parasympathetic postganglionic fiber and part ofsympathetic postganglionic fiber, which acts on cholinergic receptors,i.e., muscarine receptor (M-receptor) and nicotine receptor(N-receptor), with strong bioactivity. Cholinergic receptor blockingagents, which can be divided into M-choline receptor blocking agents andN-choline receptor blocking agents, act to block the choline receptor.M-choline receptor blocking agents can block the choline receptors onthe effectors dominated by the central and the postganglioniccholinergic nerve, which exhibits pseudo-mentation of the central nerve,chalasia of the smooth muscles, inhibition of glandular secretion,mydriasis, speeded cardiac rhythm and the like, and thus, they haveextensive pharmacological functions and clinical uses.

At present, nearly all of M-choline receptor blocking agents aretropine-base alkaloids or artificial atropine substitutes. Due to theirextensive pharmacological effects, when they are used for a certaineffect, other effects become side effects, especially the psychomimeticeffect. This limits their clinical uses and thus, the anticholinergicagents should have selectivity, i.e., maintaining their anticholinergiceffect while reducing the adverse effect of the center nervepsychomimetic effect.

Up to this date, there is no report about the quinuclidine compoundshaving a quaternary ammonium group as disclosed in the presentinvention, nor is there any report about the use thereof in blockingcholinergic receptor as an anticholinergic agent.

SUMMARY OF THE INVENTION

To overcome the defects of the prior medicaments and techniques, oneaspect of the present invention is to provide a novel quinuclidinecompound having quaternary ammonium group.

Another aspect of the present invention is to provide a method ofpreparing the quinuclidine compound having quaternary ammonium group.

A further aspect of the present invention is to provide one or morepharmaceutical composition(s) comprising the above compound andpharmaceutically acceptable carriers, such as tablets, capsules,aerosols, sprayers, injections or slow-release formulations.

Yet another aspect of the present invention is to provide a use of theabove compound in preparing anticholinergic agents.

For the aspects of the present invention, the following technicalsolutions are provided:

The present invention relates to a novel compound of Formula I:

wherein,R₁ is selected from saturated straight-chain alkyl and cycloalkylcontaining 1 to 12 carbon atoms,R₂ is selected from saturated straight-chain alkyl or straight-chainalkyl containing 1 to 12 carbon atoms, andX is selected from halide ion, pharmaceutically acceptable acid radicalssuch as organic and inorganic acid radicals.

The method of preparing the compound of Formula I of the presentinvention comprises reacting phenylalkylethylene oxide and2-quinuclidinol with strong base in an organic solvent, then isolatingthe diastereoisomer by chromatography, and finally reacting withhalogenated alkane.

Specifically, the method of preparing the compound of Formula Icomprises the following acts:

(A) reacting phenylalkylethylene oxide and 2-quinuclidinol with strongbase in DMSO;

(B) reacting the product of act (A) with halogenated alkane to prepareracemic compound containing quaternary ammonium group;

(C) isolating the product of act (A) by chromatography to prepare a pairof diastereomeric compounds and corresponding pure optical isomercompounds.

(D) reacting the products of act (C) with halogenated alkane,respectively, to prepare stereoisomeric compounds containing quaternaryammonium group.

The present invention also relates to a pharmaceutical compositioncomprising an effective amount of the compound of Formula I andpharmaceutically acceptable carriers.

According to the pharmacological study, the compound of Formula I of thepresent invention has an activity of blocking cholinergic receptor, andthe compound of the present invention exhibits a notable inhibition tospecific allergic asthma of guinea pigs. More importantly, the compoundof the present invention cannot penetrate through the blood-brainbarrier or enter into the central nerve system, and thus, it does notpresent an adverse effect of the center nerve psychomimetic effect.

The compounds of the present invention are cholinergic receptor blockingagents that cannot enter into the central nerve system, and they can beused in treatment of bronchial asthma, chronic obstructive pulmonarydisease, common cold, rhinitis, peptic ulcer, diarrhea, arrhythmia, etc.

The pharmaceutical composition comprising an effective amount of thecompound of the present invention can be prepared by using commoncarriers known in the art.

The compound of the present invention or the composition thereof can beadministered via oral or parenteral methods. The oral formulationsinclude tablet, capsule, coating, pulvis, and oral liquid. Theparenteral formulations include aerosol, sprayer, drop, injection, andsuppository. These formulations are prepared by common methods known tothe skilled in the art. The dressings for the preparation of tablet,capsule, coating, pulvis, are common assistants, including, for example,starch, dextrin, microcrystalline cellulose, pregelatinized starch,gelatin, acacia gum, methyl cellulose, ethyl cellulose, hydroxypropylcellulose, sodium carboxymethyl cellulose, silica, and polyethyleneglycol. The solvents for liquid formulations are water, ethanol,propylene glycol, vegetable oils such as corn oil, arachis oil, andolive oil, etc. The formulations of the compounds of the presentinvention can also contain other assistants, such as surfactant,lubricant, disintegrant, preservative, odor-masking agent and colorant.

The dosage of the compound of Formula I of the present inventioncontained in tablet, capsule, coating, aerosol, sprayer, injection andsuppository is calculated based on the amount of the compound presentedin unit formulation. The unit formulation generally contains 1-5000 μgof the compound of Formula I of the present invention.

For the treatment of bronchial asthma, chronic obstructive pulmonarydisease, common cold, rhinitis, and the like, an adult patient could beadministered with the compound of the present invention by spray, onceor separately, with a dosage of 1-1000 μg, preferably 1-100 μg per day.

PREFERRED EMBODIMENTS OF THE INVENTION

The present invention is further described by the following examples.However, these examples cannot be taken as the limitation of the presentapplication. The measurement instruments used herein are listed below:melting-point is measured by XRC-1 micromelting point apparatus withoutcalibration of thermometer; NMR spectroscopy is measured by BrukerARX500 nuclear magnetic resonance analyzer with TMS as the internalstandard; the mass spectrum is determined by Nicoler FTMS-2000Gapparatus.

Example 1 The preparation of3-quinuclidinyl-(2′-phenyl-2′-cyclopentyl-2′-hydroxyl)ethyl Ether (1)

9.3 g 1-phenyl-1-cyclopentyl ethylene oxide was dissolved in DMSO. To 64ml of DMSO was dissolved 6.35 g quinuclidinol, then 2.5 g sodium hydridewas added. After stirring for 1 hour, the solution was cooled to roomtemperature. Then dropped with a solution of 1-phenyl-1-cyclopentylethylene oxide in DMSO, and stirred for additional 3 hours. Aftercooling to room temperature, the solution was extracted with ether, andthe ether layer was extracted with 6N HCl. The acid aqueous layer wasthen basified by 20% NaOH, and then extracted with ether. The etherlayer was dried over anhydrous sodium sulfate overnight, the solvent wasevaporated, and the product was purified through distillation with ayield of 54%.

Example 2 The preparation of3-(N-methyl-quinuclidinyl)-(2′-phenyl-2′-cyclopentyl-2′-hydroxyl)ethylEther Bromide (2)

The compound (1) obtained in Example 1 was dissolved in anhydrousethanol, and then aerated with excess bromomethane, and reactedovernight. After evaporation of the solvent, the product wasrecrystallized with acetone to give a white solid with a yield of 75%.The melting point is 166-168° C.; ¹HNMR (CDCl₃): 7.42 (d, 2H), 7.29 (g,2H), 7.20 (t, 1H), 4.29 (m, 1H), 3.96 (br, 1H), 3.85 (m, 1H), 3.70 (m,4H), 3.30 (d, 1H), 3.22 (s, 3H), 3.11 (m, 2H), 2.25 (m, 2H), 1.96 (m,2H), 1.63 (m, 4H), 1.44 (m, 4H), 1.26 (m, 2H). MS (m/z): 410 (M⁺); 175,726 (B).

Example 3 The Preparation of I-Type Diastereoisomer of3-(N-methyl-quinuclidinyl)-(2′-phenyl-2′-cyclopentyl-2′-hydroxyl)ethylEther Bromide (3)

Compound (1) was isolated by preparative silica gel plate withCHCl₃:methanol:ammonia (4:0.8:0.15) as the developer. After collectingthe chromatographic band with high R_(f) value, the eluted product wasaerated with excess bromomethane, and reacted overnight. Afterevaporation of the solvent, the product was recrystallized with acetoneto give a white solid with a yield of 30%. The melting point is 149-151°C.

Example 4 The Preparation of II-Type Diastereoisomer of3-(N-methyl-quinuclidinyl)-(2′-phenyl-2′-cyclopentyl-2′-hydroxyl)ethylEther Bromide (4)

Compound (1) was isolated by preparative silica gel plate withCHCl₃:methanol:ammonia (4:0.8:0.15) as the developer. After collectingthe chromatographic band with low R_(f) value, the eluted product wasaerated with excess bromomethane, and reacted overnight. Afterevaporation of the solvent, the product was recrystallized with acetoneto give a white solid with a yield of 30%. The melting point is 160-162°C.

Example 5 In Vitro Anti-Acetylcholine Effect of the Compound of thePresent Invention

This experiment adopts the methods known to the skilled in the art. Anex vivo ileum specimen was prepared and suspended in a 30 ml bath filledwith Tyrode's solution. The nutrient fluid was aerated with a mixed gasof 95% O₂ and 5% CO₂, and maintained a constant temperature of 37° C.,then an irritating electrode was equipped. Irritation was performed witha square wave with a frequency of 0.1 times/s and duration of 1millisecond. The ileum will take place a transient contraction upon oneirritation. Before changed to other Tyrode's solution containingdifferent medicament, it is necessary to wash with the Tyrode's solutionfor three times and carry out a blank irritation. Consequently, theileum contraction response resulted from electric irritation iscompletely blocked in Tyrode's solutions containing 10⁻⁷ g/ml ofatropine sulfate, the compounds of Example 2, Example 3 and Example 4,respectively.

The preparation of the aerosol containing the compound of the presentinvention:

Example 6

0.28 g of the compound of the present invention, 35 g propylene glycol,382 g ethanol and 983 g propellant are sealed into containers withproportional valves. Each container has 10 g of the above mixture, andeach spray is 100 mg with 20 μg of the compound of the presentinvention. The propellants are selected from the group consisting oftrichloromonofluoromethane, dichlorodifluoromethane,dichloromonofluoromethane, monochlorodifluoromethane,dichlorotetrafluoroethane, chloropentafluoroethane,chlorodifluoroethane, difluoroethane, octafluorocyclobutane and themixture thereof.

Example 7

0.28 g of the compound of the present invention, 42 g propylene glycol,210 g anhydrous ethanol, 231 g dichlorodifluoromethane and 971 gdichlorotetrafluoroethane are sealed into containers with proportionalvalves. Each container has 10 g of the above mixture, and each spray is100 mg with 20 μg of the compound of the present invention.

Example 8 The Effect of the Aerosol Containing the Compound of thePresent Invention in Treatment of the Specific Allergic Asthma of GuineaPigs

This experiment adopts the methods known to the skilled in the art. 30healthy guinea pigs with body weights of 200-220 g are picked in theexperiment. Each guinea pig is intraperitoneally injected with 1.0 ml10% ovalbumin physiological saline solution (100 mg of ovalbumin).Thereafter, they are randomly separated into blank control group,positive control group [Atrovent (IpratropiumBromide aerosol), 10 ml percontainer, 20 μg per spray, made by Boehringer Ingelheim of Germany,Batch No. 104015, manufacture date: June, 2001, term of validity: June2004], aerosol group of the compound of Example 2, aerosol group of thecompound of Example 3, and aerosol group of the compound of Example 4,with ten guinea pigs each group. The guinea pigs are administrated byspraying into the respiratory tract once a day for 5 days continuouslyfrom the 6^(th) day after the injection. Then they are put into sealedcages separately and 0.5% ovalbumin physiological saline solution wassprayed evenly into the cages by ultrasonic atomizer for 30 s. The timeinterval between the spray of the ovalbumin physiological salinesolution and the contraction of the abdominal muscle, also known as theasthma latent period, is observed and recorded. The obtained data aret-tested to demonstrate the differences among the groups.

Results: 10 days after the guinea pigs were intraperitoneally injectedwith ovalbumin, when they contacted with the same antigen again, theantigen-antibody reaction that mainly involves dropsy and spasm of therespiratory tract occurs, which is called specific allergic asthma. Theexperiment demonstrates that the aerosol of the present compoundexhibits notably inhibition to this specific reaction, in which theasthma latent period is obviously prolonged as compared to that of theblank control group, P<0.01. The results are listed in Table 1 below.

TABLE 1 The effect of the aerosol containing the compound of the presentinvention on allergic asthma of guinea pigs (s X ± SD) Group n Dosage(μg · kg⁻¹) latent period (s) Blank control 10 — 124.00 ± 21.66 Positive control 10 100 235.40 ± 45.15** aerosol of the compound of 10100 248.90 ± 38.24** Example 2 aerosol of the compound of 10 100 243.50± 42.13** Example 3 aerosol of the compound of 10 100 231.60 ± 37.30**Example 4 Compared with the blank control group **P < 0.01

INDUSTRIAL APPLICABILITY

According to the above experimental results, those skilled in the artwill understand that the compounds of the present invention can blockthe mammalian M-choline receptor. In addition, the compounds of thepresent invention have a promising prospect in preparing M-cholinereceptor blocking agents for mammals, including human.

1. A method of blocking cholinergic receptors comprising administeringto a patient a compound having quaternary ammonium group of Formula I:

wherein, R₁ is selected from saturated straight-chain alkyl andcycloalkyl containing 1 to 12 carbon atoms, R₂ is selected fromsaturated straight-chain alkyl and straight-chain alkyl containing 1 to12 carbon atoms, and X is selected from halide ion, organic andinorganic acid radicals.
 2. The method of claim 1, wherein R₁ iscyclopropyl, cyclopentyl or cyclohexyl; R₂ is methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl or t-Butyl; X is fluorine, chlorine,bromine, iodine, methanesulfonic acid radical, paratoluenesulfonic acidradical, or other pharmaceutically acceptable acid radicals.
 3. Themethod of claim 1, wherein R₁ represents cyclopentyl; R₂ representsmethyl; X represents bromine.
 4. The method of claim 1, wherein aconfiguration of the compound is diastereoisomer.
 5. The method of claim1, wherein a configuration of the compound is pure optical isomer.
 6. Amethod of treating specific allergic asthma comprising administering toa patient a compound having quaternary ammonium group of Formula I:

wherein, R₁ is selected from saturated straight-chain allyl andcycloalkyl containing 1 to 12 carbon atoms, R₂ is selected fromsaturated straight-chain alkyl and straight-chain alkyl containing 1 to12 carbon atoms, and X is selected from halide ion, organic andinorganic acid radicals.
 7. The method of claim 6, wherein R₁ iscyclopropyl, cyclopentyl or cyclohexyl; R₂ is methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl or t-Butyl; X is fluorine, chlorine,bromine, iodine, methanesulfonic acid radical, paratoluenesulfonic acidradical, or other pharmaceutically acceptable acid radicals.
 8. Themethod of claim 6, wherein R₁ represents cyclopentyl; R₂ representsmethyl; X represents bromine.